SortStack #112 — 2026-09-29

By weight · Order from lightest to heaviest.

1. A one-euro coin 7.5 g

   Its two-metal design is not just style — the distinct layers give vending machines an electromagnetic signature to verify.

2. A AAA alkaline battery 11.5 g

   Despite the tiny package, a fresh AAA stores enough energy to hoist an adult human several meters into the air.

3. A liter of water 1 kg

   The kilogram was originally defined in the 1790s as the mass of exactly this much water — the tie was only fully broken in 2019.

4. An adult red fox 5.2 kg

   Red foxes may use Earth's magnetic field to aim their famous pouncing dives — they prefer striking toward the northeast.

5. An upright piano 220 kg

   Inside is a cast-iron plate holding strings at a combined tension of roughly 18 tonnes of pull.

6. The London Eye observation wheel 2.1K t

   It was meant to stand for just five years when it opened in 2000; instead it became the UK's most popular paid attraction.

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